I put a demonstration together.
The first two pictures show both methods.
Can anyone tell me why the 'green' screw is any better than the clamp screw?
Someone also asked Don why he takes the clamp out, well I do too and I think this picture illustrates why.
If there is going to be a short in a box with MC clamps it will be where the wires are pushing against the top of the extra clamp. Take that clamp out and there is much more room.
I had to use a wire nut on the box with the grounding pigtail as it is almost imposable to wrap the incoming ground wire around the screw due to the small space.
I consider myself a craftsman, I take pride in my job and I respect the code.
George's original post.
I maintain that the Contractor should be using the 8-32 hole provided for installing a GREEN screw and not use the cable clamp screw what-so-ever for grounding. I don't think he should even use the silver colored cable clamp screw in the hole provided for the GREEN ground screw. I need something official for a reference.
The answer is there is
nothing in the NEC that prohibits what the contractor is doing as long as the clamp is removed from the screw.
It's that simple.
JMO, Bob